Machine for filling luncheon dough into mold cans

ABSTRACT

An stuffing horn for filling food products into molds that extends completely within a mold and feeds the food product into the mold as it is retracted. A close-fitting cover plate is then put on the mold while the stuffing horn holds the food product in the mold under pressure.

Unlte States Patent 3,845,793

Good [4 Nov. 5, 11974- l MACHINE FOR FILLING LUNCHEON 2,058,118 l0/l936White I N/392 DOUGH N O O CANS 2,104,843 l/l938 222/523 2,l94,948 3/l940Lenzkc ll/392 Inventor: Paul Good, Luthervllle, 3,543,682 12/1970 FIrrow 222/523 [22] Filed: May 1972 FOREIGN PATENTS OR APPLICATIONS PP240,599 149,261 12 1952 Australia 222/523 Related U.S. Application Data[62] Division of Ser. No. 40,l35, May 28, 1970, Pat. No. Primary i e 0S. Bell,

3,688,682. Attorney, Agent, or Firm-Frederick W. Turnbull [52] U.S. Cl.141/67, l4l/392 [51] lint. Cl B65b 3/14 [57] ABSTRACT 8 F l [5 1 1e 2 gzg g figg An stuffing horn for filling food products Into molds 99/349351 226/234 I that extends completely within a mold and feeds the 291/45food product into the mold as it is retracted. A closefitting coverplate is then put on the mold while the [56] References Cited stuffinghorn holds the food product in the mold under UNITED sTATEs PATENTSpressure 1,701,309 2/1929 Rush 222/523 3 Claims, 10 Drawing Fiaures l 2l A I l M ll 1 1R \SUPPLV EXHQUST a rlllllllll. -A

AIR SUPPLY unv SISIM 3.845793 PMENTED sum 1 or 4' PATENTEDmJv 51974 3,

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n12 SUPPLY EXHAUST AIR SUPPLY MACHINE FOR FILLING LUNCHEON DOUGH INTOMOLD CANS This is a divisional application of application Ser. No.40,135, filed 25 May 1970 now issued as US. Pat. No. 3,688,682.

The present invention relates to an apparatus for filling food productsinto molds for subsequent processing and, in particular, to an automaticmachine for spraying mold release oil into the molds, automaticallyfilling the molds and automatically positioning tight fitting lids ontomolds whole holding the molds under pressure; such that after cookingand chilling, uniformity of cross-sectional dimensions and uniformity ofdensity along the length of the loaves is greatly improved over methodspresently used.

It is presently common practice to fill molds with food products, cookand chill the loaves, then remove the loaves from the molds for slicingand grouping the slices into groups or stacks of predetermined weights.In this connection, various statutes and regulations require that eachgroup of slices must have the weight specified on the packaging whenoffered to the consumer. For efficient production, the weights of thestacks of food must not greatly exceed the specified weight. The weightin excess of the specified weight is usually referred to as give-awayweight. With modern slicing methods, the give-away can be reduced byproducing loaves of uniform density and cross-section along theirlength. The lids and molds that are normally used allow leakage and lossof moisture at the ends of the loaves such that the dozen or so slicesat the ends of the loaves are underweight and the stacks of food formedfrom these slices will be underweight. They must be manually correctedby adding a partial slice of product or else by adding a thicker sliceof product to bring the stack to the required weight. This correction isnot only costly labor-wise, but also detracts from the appearance of theproduct.

The usual methods of producing loaves of food products produce loavesthat are not uniform in crosssection and density along the length of theloaves because there are no provisions for maintaining a pressure in themolds while the lids are positioned on the molds. For example, the moldstuffing apparatus shown in Hawley U.S. Pat. No. 3,373,777 hasprovisions for developing a pressure in the molds as they are beingstuffed, but it is not possible to maintain a uniform I stuffingpressure along the length of the loaves because considerable clearanceis required between the inside of the molds and the rigid type stuffinghorn. As the food product is stuffed, considerable pressure is developedin the mold resulting in leakage between the horn and the inside of themold. To minimize this, the horn is made quite long to increase thelength of the leakage path and therefore reduce the leakage rate.However, as the molds are filled and as the horn nears the filling endof the molds, the leakage path along the horn gradually decreases tozero length, so the leakage near the end of the loaf becomes excessive.

Furthermore, there are no provisions for holding this pressure until thelid is placed on the mold. In operating this apparatus, a mold is placedupon a slidable carriage, the mold is then slid over the stuffing horn,the operator opens a valve in the food supply line to fill the mold, thefilled mold is then removed from the apparatus and the lid is manuallypositioned on the mold.

The instant invention incorporates a flexible horn seal that expands tocontact the sides of the molds such that full mold pressure ismaintained during the stuffin g of the full length of the loaves, and isalso maintained while the lids are automatically placed on the molds.

The existing types of molds and lids are not suitable for automaticfilling and automatic loading of the lids. Furthermore, they do notprovide an adequate seal to prevent leakage of moisture and shrinkage atthe ends of the loaves.

An object of this invention is to produce a mold filling method andmachine that will greatly reduce the labor required for the fillingoperation.

Further objects of this invention are to produce a method and moldfilling machine that will produce loaves of food product which are veryuniform in crosssection and density along the length of the loaves, willreduce the usual shrinkage during cooking and chilling and will increasethe amount of food product that can be put into the molds.

A further object of this invention is to produce a mold filling machinethat will automatically maintain a predetermined pressure on the foodproduct in the mold during the stuffing operation.

This automatic mold filling machine improves the quality of the foodloaves and also reduces the labor cost to about 50 percent of the usualmold filling labor cost.

The means by which the objects of this invention are obtained aredescribed more fully with reference to the accompanying drawings inwhich:

FIG. 1 is an enlarged view, partly in cross-section, of j FIG. 2a is aview of a spider used in the inlet end of the horn shown in FIG. 2;

FIG. 2b is an enlarged cross-sectional view of a detail shown in FIG. 2;

FIG. 2c is a schematic view of the air system and modulating valve usedfor the operation of the stuffing horn;

FIG. 3 is a front view of an end of a frame for being fitted to an endof a can for holding a cover plate;

FIG. 4 is a cross-sectional view taken on the line 6-6 of FIG. 3;

FIG. 5 is a side view of a cover plate;

FIG. 6 is a cross-sectional detail view of the frame of FIG. 5 securedto a can; a

FIG. 7 is a graph showing comparison curves of different methods andstuffing.

As shown in FIG. 1, the stuffing horn is composed of an outer tube 30having at one end a threaded fitting 32 for being attached to a foodpump and an inner tube 34 telescoped within the outer tube 30. Sealingrings 34a are secured to inner tube 34 and slide on the inner wall oftube 30 which also provides an end bushing 30a. A block 34b secured tothe end of tube 34 within flexible sealing cup 36 serves as a stop forlimiting the movement of tube 34 adjacent the far cover in a mold toprevent undue distortion of cup .36. The open end of tube 34 is attachedto a flexible cup 36 having on its outer surface ribs 38 which extendparallel to the longitudinal axis of tube 34.

Pneumatically actuated lever and latch means 39 is engageable in a notchon tube 34 to assist the final phase step in the withdrawal of tube 34from a mold,

and holding the tube against advancing food pressure while in startingposition.

In the modification of FIG. 2, the horn is composed of an outer tube 40and an inner tube 42 telescoped within tube 40. A threaded fitting 43 issecured to the inlet end of outer tube 40 for attachment to a food pump.A spider 44, FIG. 2a is mounted on this end of the tube and supports arod 44a coaxially within the tube. Stop block 44b is slidably mounted onrod 44a and blocks the inlet end of inner tube 42 when the latterapproaches its starting position. Bearing ring 42a is secured to tube 42and slides on the inner wall of tube 40. Tube 40 has a bearing block 40aat its outer end in which tube 42 slides. Tube 40 has a port 40b towhich is attached a compressed air hose 400. Food entering throughspider 44 will bear against both bearing ring 42a and block 44b and willstart the movement of tube 42 outwardly of tube 40. When block 44b isstopped by nut 44c on rod 44a, the tube 42 is opened to the foodpressure, but the friction of the food on the inner wall of the tube 42prevents the food from actually flowing through the tube until the tubeis fully extended and the tube contacts the bottom of mold 22.

To control the food pressure in the mold, compressed air at a suitablepredetermined pressure is introduced through port 40b and pushes againstseal assembly 420 to reduce the effect of the frictional drag of thefood on the tube 42 and the food stuffing pressure against seal assembly42b. Thus, for very stiff food that creates a heavy frictional drag ontube 42, the air pressure admitted through port 40b would be higher thanfor lighter foods that create less frictional drag.

When the automatic food pressure system of FIG. 20 is used, thecompressed air entering port 40b is modulated in response to valve 160.In this system, regulated compressed air is supplied to holding cylinder104 through pressure regulator 161. Pressure regulator 161 is set asrequired to obtain the desired food pressure in the mold. For example,if the cross-sectional area of the food mold is 20 square inches, theholding cylinder cross-sectional area is 5 square inches, and thedesired food pressure is 12 pounds per square inch, the regulator 161would be set at 48 pounds per square inch. Thus, the holding cylinderforce will hold the mold against the pressure plate 49 until thepressure of the food in the mold exceeds 12 PSI When this happens, themold moves to the left to open modulating valve 160 and admit air to thestuffing horn through port 40b until the pressure against the stuffinghorn seal ring 42c is sufficient to reduce the food pressure to 12 PSI.The mold then moves toward the pressure plate 49 and reduces the rate offlow of the air to the stuffing horn. In this manner, the air flow tothe stuffing horn is modulated as the mold moves to and from thepressure plate 49 such that when the mold moves to the extreme leftposition the flow through the modulating valve 160 is maximum, and whenthe mold is held firmly against the pressure plate 49 the flow is zero.Valve 162 is shown held open by force A during the stuffing operation.When the mold is filled force A is released to shut off the air supplyto valve 160 and exhaust the air from the stuffing horn through port40b.

Radially directed ports 45 adjacent the outlet end of tube 42 directfood against flexible cup 46 which also has external ribs 48.

As shown in FIG. 2b, a pressure plate 49 is mounted on the end frame 490fastened to beam 17, FIG. 1. At

the end of a filling stroke, cup 36, or 46, bears tightly against plate49 and extends slightly into the mold 22 to prevent the loss of foodpressure in filled mold 22 while the mold is being closed by a cover Q.As the cover C is positioned on the mold 22, the cover compresses theseal enough to move it out of the path of the cover. a

As shown in FIGS. 3 to 6 each mold has at each end a frame 50 welded tothe end of the mold. This frame is adapted to fit over the end of a mold22 by means of a shoulder 52. As shown in FIG. 3 the inner side of theframe outwardly of a mold has a pair of grooves 54 for receiving a coverplate C.

As shown in FIG. 5, the cover plate is composed of a spring metal platehaving flat end portions 56 and 58, respectively, and a middle centerportion 60. When a cover plate C is driven into the grooves 54 as shownin FIG. 4 the plate of spring metal has its curved portion 60 flattenedso it seals the end of the mold to prevent the escape of any significantamount of food. Hole 59 serves to receive a hook to pull the cover fromthe mold in order to remove a cured loaf therefrom.

With reference to FIG. 1, when the oiled mold is in the stuffingposition the food supply pump is started and the latch means 39 swingsto the left and upwardly to release the inner tube 34 such that theinner tube 34 is then advanced into the mold 22 by means of the foodpumped into tube 31. The friction of the food on the inner wall of tube34 along with the food pressure on the inlet end of the inner tube issufficient to move the tube outwardly of the outer tube while beingfilled with food. As the cup 36 moves through the mold, the outer edgeof the cup is slightly cleared from the inner wall of the mold so thatair can escape from the mold. When stop block 34b on tube 34 reaches thecover plate C at the end of the mold the pressure of the food causes thefree edge of the cup 36 to expand outwardly as shown in dotted lines inFIG. 1 so that it contacts the inner wall of the mold. The pressure oofthe food then overcomes the friction between the food and the inner wallof the tube so that as the mold is being filled the tube 34 will beretracted. When the mold is filled and substantially at the same timethe free edge of the cup 36 reaches the end of the mold, the food pumpis shut off, the latch means 39 engages the inner tube 34 to hold thetube 34 in its fully retracted position, and the piston means in stand18a is activated so as to drive a closing cover plate C into the end ofthe filled mold. The reel 12 is then indexed away from the horn 30 andthe filled mold then manually removed from the reel. At the same time, anew empty mold previously sprayed with releasing oil is brought intoposition for filling.

With reference to FIG. 2, when an empty mold is ready for stuffing, thefood supply pump is started and the latch means 39 disengages the innertube 42 such that the inner tube 42 is then advanced into the mold 22 bymeans of food pumped into the tube 40d against 'the reel 42b and theblock 44b. As the tube 42 extends and the block 44 reaches the coverplate C at the end of the mold, as previously described, a modulatedflow of compressed air flows into port 40b to control the food pressurein the mold.

When the mold is filled, and at substantially the same time the freeedge of the cup 46 reaches the end of the mold, the block 44b closes offthe flow of food into the tube 42, the food pump shuts off and the latchmeans 39 engages the inner tube 42 to hold the tube 42 in its fullyretracted position. Nut 440 can be adjusted as desired to advance orretard the closing of tube 42 as the tube 42 nears its fully retractedposition.

The advantages of this invention are first of all in that the food isfilled into the mold under pressure. This is made possible by the actionof the stuffing horn and by the tight seals given by the cover plates C,C and C" shown in FIGS. 3, 4, and 5. The food is tightly packed into themold using about one-half the amount of labor heretofore needed to sprayand fill the molds. The loaves are very uniform in cross-section anddensity along the length of the molds and therefore the stacks of foodwhich have been sliced from the loaves are much more uniform in weightthen ordinary. Due to the pressure in the mold, about 5 to 10 percentmore food can be filled into the mold than customary. The tight sealsgiven by the covers C and C and C reduce the normal shrinkage in theluncheon loaves during subsequent cooking.

A comparison of test results on luncheon meats obtained by thisinvention with the prior art is given in the curves of FIG. 7. Curve Gis according to the instant invention, curve R is for molds ordinarilyused by meat process manufacturers and curve H is for the mold of Hawleyet al., U.S. Pat. No. 3,166,007. In making loaves of luncheon meat,every effort is made to reduce the give-away in the finished stacks ofmeat slices ready for sale. Heretofore, considerable shrinkage has beenexperienced in the luncheon loaves especially at the ends of the loavesbecause of moisutre loss through loose covers. This shrinkage means thatat the end of the loaves there are several stacks of meat which areconsiderably underweight. This requires manual wegith correction tobring them to specified weight. The curve G for the mold of the instantinvention shows that from the slices obtained from the machine of thisinvention, 34 stacks of slices out of 36 stacks fell within athreesixteenths oz. tolerance. Curve R shows that for regular moldstwenty-seven out of thirty-three stacks were within a three-sixteenthsoz. tolerance, and curve H shows that 23 out of 31 stacks were withinthis tolerance. Curve R shows extreme shrinkage at the righthand end ofregular molds, and curve H shows extreme shrinkage on the lefthand endof the Hawley et al. mold.

In addition to the desirability of having accurate weights in the stacksof slices, it is also important that the loaves are dimensionallyuniform so that the semirigid packaging film will not wrinkleexcessively as will occur in luncheon meat stacks which are undersizedbecause of the excessive shrinkage at the ends of the loaves.

Shrinkage measuring tests have shown that the average shrinkage for onehundred regular molds of curve R was 7% percent, while the averageshrinkage for the molds of this invention was precent, which is a 2%percent shrinkage savings for this invention. This amounts to aconsiderable dollar savings when considering the high volume that thenormal meat packer processes.

Another advantage is in that, because of the pressure filling of thefood into the molds, the molds of this invention can hold from 5 to 10percent meat than here tofore used filling methods. This results in anaverage additional reduction of the whole labor processing costs ofabout 7 /2 percent.

Having now described the means by which the objects of this inventionare obtained, I claim:

1. A stuffing horn for filling a mold with food comprising an outer tubeand an inner tube to form a telescopic horn for passage of food underpressure said inner tube extending beyond one end of said outer tube,said inner tube being spaced inwardly from said outer tube, sealing ringmeans mounted on said inner tube at its end within said outer tubeslidably engaging the inner surface of said outer tube, and bearingmeans at the end of the outer tube surrounding said inner tube toslidably support said inner tube, whereby said inner tube may betelescopicably extended into a mold to be filled and retracted from saidmold as the food passes through the stuffing horn into said mold underpressure.

2. A stuffing horn as in claim 1, further comprising port means in saidouter tube for supplying compressed air into said space, and stop blockmeans in said outer tube for closing the food inlet end of said innertube when said inner tube is fully retracted into said outer tube.

3. In a stuffing horn for filling a cooking mold with a food product ofthe type in which the stuffing horn is inserted into the mold to aposition adjacent the bottom of said mold and is retracted from the moldas the mold is filled, said stuffing horn being tubular to deliver thefood product into the mold under pressure, the novelty comprising aflexible sealing cup having its free edges extending toward the closedbottom of said mold and of a size, when not under pressure, slightlyless than the interior size of said tubular mold so as to pass freelyinto said mold as the horn is extended into said mold, said flexiblesealing cup being exteriorly ribbed so that upon flexible expansion ofsaid sealing cup under the pressure of the food product being forcedthrough said horn into said mold only the ribs of said flexible sealingcup will contact the interior walls of said mold as said stuffing hornis retracted from said mold.

1. A stuffing horn for filling a mold with food comprising an outer tubeand an inner tube to form a telescopic horn for passage of food underpressure said inner tube extending beyond one end of said outer tube,said inner tube being spaced inwardly from said outer tube, sealing ringmeans mounted on said inner tube at its end within said outer tubeslidably engaging the inner surface of said outer tube, and bearingmeans at the end of the outer tube surrounding said inner tube toslidably support said inner tube, whereby said inner tube may betelescopicably extended into a mold to be filled and retracted from saidmold as the food passes through the stuffing horn into said mold underpressure.
 2. A stuffing horn as in claim 1, further comprising portmeans in said outer tube for supplying compressed air into said space,and stop block means in said outer tube for closing the food inlet endof said inner tube when said inner tube is fully retracted into saidouter tube.
 3. In a stuffing horn for filling a cooking mold with a foodproduct of the type in which the stuffing horn is inserted into the moldto a position adjacent the bottom of said mold and is retracted from themold as the mold is filled, said stuffing horn being tubular to deliverthe food product into the mold under pressure, the novelty comprising aflexible sealing cup having its free edges extending toward the closedbOttom of said mold and of a size, when not under pressure, slightlyless than the interior size of said tubular mold so as to pass freelyinto said mold as the horn is extended into said mold, said flexiblesealing cup being exteriorly ribbed so that upon flexible expansion ofsaid sealing cup under the pressure of the food product being forcedthrough said horn into said mold only the ribs of said flexible sealingcup will contact the interior walls of said mold as said stuffing hornis retracted from said mold.